Solid-state imaging device, electronic apparatus, and method for manufacturing the same

ABSTRACT

Photoelectric conversion elements disposed on an imaging surface of a substrate, receiving light incident on a light receiving surface and performing photoelectric conversion to produce a signal charge; electrodes interposed between the photoelectric conversion elements; and light blocking portions provided above the electrodes and interposed between the photoelectric conversion elements. The light blocking portions include an electrode light blocking portion formed to cover the corresponding electrode, and a pixel isolation and light blocking portion protruding convexly from the upper surface of the electrode light blocking portion. The photoelectric conversion elements are arranged at first pitches on the imaging surface. The electrode light blocking portions and the pixel isolation and light blocking portions in the light blocking portions are arranged at second and third pitches, respectively, on the imaging surface. At least the third pitch increases with distance from the center toward the periphery of the imaging surface.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a solid-state imaging device, anelectronic apparatus, and a method for manufacturing the same.

2. Description of the Related Art

A digital video camcorder, a digital still camera, or any other similarelectronic apparatus includes a solid-state imaging device. Thesolid-state imaging device is, for example, a CCD (Charge CoupledDevice) image sensor.

For example, a CCD image sensor has an imaging region provided on asubstrate. The imaging region has a plurality of pixels arranged in thehorizontal and vertical directions and forming a matrix. In the imagingregion, a plurality of photoelectric conversion elements, which receivessubject image light and produces signal charges, is formed incorrespondence with the plurality of pixels. For example, photodiodesare formed as the photoelectric conversion elements.

Vertical transfer registers are provided between columns formed of theplurality of photoelectric conversion elements arranged in the verticaldirection in the imaging region. Each of the vertical transfer registershas a plurality of transfer electrodes facing a vertical transferchannel region via a gate insulating film and transfers in the verticaldirection the signal charges read from the corresponding photoelectricconversion elements through charge readout portions. A horizontaltransfer register then sequentially transfers in the horizontaldirection the signal charges having been transferred for each horizontalline (a row of pixels) through the corresponding vertical transferresister, and an output section outputs the signal charges (seeJP-A-7-50401, for example).

In the solid-state imaging device described above, electrode lightblocking films that block light incident on the vertical transferresisters are provided in the imaging region in order to prevent smearor other problems.

Further, a variety of techniques have been proposed to prevent shading,color mixing, and other problems from occurring in a captured image (seeJP-A-7-50401, JP-A-10-163462, JP-A-2006-196553, and JP-A-2001-189440,for example).

SUMMARY OF THE INVENTION

A solid-state imaging device and other similar devices are typicallyrequired to be reduced in size. As a result, among a plurality of pixelsarranged in the imaging region of a solid-state imaging device, pixelspositioned in the periphery of the imaging region receive incident lightinclined to the direction perpendicular to the imaging region, and theinclination angle increases as the size of the imaging device decreases.That is, the angle of incidence at both ends of the angle of viewincreases as the size of the imaging device decreases.

It is therefore sometimes difficult to sufficiently suppress shading,color mixing, and other problems, resulting in decrease in image qualityof a captured image in some cases.

Thus, it is desirable to provide a solid-state imaging device, anelectronic apparatus, and a method for manufacturing the same capable ofimproving the image quality of a captured image.

A solid-state imaging device according to an embodiment of the inventionincludes a plurality of photoelectric conversion elements disposed on animaging surface of a substrate, each of the photoelectric conversionelements receiving light incident on a light receiving surface andperforming photoelectric conversion to produce a signal charge, aplurality of electrodes interposed between the photoelectric conversionelements arranged on the imaging surface of the substrate, and aplurality of light blocking portions provided above the plurality ofelectrodes and interposed between the photoelectric conversion elementsarranged on the imaging surface of the substrate. Each of the lightblocking portions includes an electrode light blocking portion formed tocover the corresponding electrode, and a pixel isolation and lightblocking portion protruding convexly from the upper surface of theelectrode light blocking portion. The plurality of photoelectricconversion elements are arranged at first pitches on the imagingsurface. The electrode light blocking portions in the plurality of lightblocking portions are arranged at second pitches on the imaging surface.The pixel isolation and light blocking portions in the plurality oflight blocking portions are arranged at third pitches on the imagingsurface. At least the third pitch increases with distance from thecenter toward the periphery of the imaging surface.

A solid-state imaging device according to another embodiment of theinvention includes a plurality of photoelectric conversion elementsdisposed on an imaging surface of a substrate, each of the photoelectricconversion elements receiving light incident on a light receivingsurface and performing photoelectric conversion to produce a signalcharge, a plurality of electrodes interposed between the photoelectricconversion elements arranged on the imaging surface of the substrate,and a plurality of light blocking portions provided above the pluralityof electrodes and interposed between the photoelectric conversionelements arranged on the imaging surface of the substrate. Each of thelight blocking portions includes an electrode light blocking portionformed to cover the corresponding electrode, and a pixel isolation andlight blocking portion protruding convexly from the upper surface of theelectrode light blocking portion. The photoelectric conversion elements,the electrode light blocking portions, and the pixel isolation and lightblocking portions are disposed at the same pitches on the imagingsurface. The pixel isolation and light blocking portions are formed insuch a way that the width in between the plurality of photoelectricconversion elements decreases with distance from the center toward theperiphery of the imaging surface.

A solid-state imaging device according to still another embodiment ofthe invention includes a plurality of photoelectric conversion elementsdisposed on an imaging surface of a substrate, each of the photoelectricconversion elements receiving light incident on a light receivingsurface and performing photoelectric conversion to produce a signalcharge, a plurality of electrodes interposed between the photoelectricconversion elements arranged on the imaging surface of the substrate,and a plurality of light blocking portions provided above the pluralityof electrodes and interposed between the photoelectric conversionelements arranged on the imaging surface of the substrate. Each of thelight blocking portions includes an electrode light blocking portionformed to cover the corresponding electrode, and a pixel isolation andlight blocking portion protruding convexly from the upper surface of theelectrode light blocking portion. The plurality of pixel isolation andlight blocking portions are formed in such a way that the width of thespaces between the plurality of pixel isolation and light blockingportions increases with distance from the center toward the periphery ofthe imaging surface.

An electronic apparatus according to yet another embodiment of theinvention includes a plurality of photoelectric conversion elementsdisposed on an imaging surface of a substrate, each of the photoelectricconversion elements receiving light incident on a light receivingsurface and performing photoelectric conversion to produce a signalcharge, a plurality of electrodes interposed between the photoelectricconversion elements arranged on the imaging surface of the substrate,and a plurality of light blocking portions provided above the pluralityof electrodes and interposed between the photoelectric conversionelements arranged on the imaging surface of the substrate. Each of thelight blocking portions includes an electrode light blocking portionformed to cover the corresponding electrode, and a pixel isolation andlight blocking portion protruding convexly from the upper surface of theelectrode light blocking portion. The plurality of photoelectricconversion elements are arranged at first pitches on the imagingsurface. The electrode light blocking portions in the plurality of lightblocking portions are arranged at second pitches on the imaging surface.The pixel isolation and light blocking portions in the plurality oflight blocking portions are arranged at third pitches on the imagingsurface. At least the third pitch increases with distance from thecenter toward the periphery of the imaging surface.

A method for manufacturing a solid-state imaging device according tostill yet another embodiment of the invention includes the steps offorming a plurality of photoelectric conversion elements on an imagingsurface of a substrate, each of the photoelectric conversion elementsreceiving light incident on a light receiving surface and performingphotoelectric conversion to produce a signal charge, forming a pluralityof electrodes interposed between the plurality of photoelectricconversion elements arranged on the imaging surface of the substrate,and forming a plurality of light blocking portions above the pluralityof electrodes and between the plurality of photoelectric conversionelements arranged on the imaging surface of the substrate. The step offorming the light blocking portions includes the steps of forming anelectrode light blocking portion that covers the correspondingelectrode, and forming a pixel isolation and light blocking portionprotruding convexly from the upper surface of the electrode lightblocking portion. In the step of forming the photoelectric conversionelements, the plurality of photoelectric conversion elements arearranged at first pitches on the imaging surface. In the step of formingthe electrode light blocking portions, the electrode light blockingportions are arranged at second pitches on the imaging surface. In thestep of forming the pixel isolation and light blocking portions, thepixel isolation and light blocking portions are arranged at thirdpitches on the imaging surface and the third pitch increases withdistance from the center toward the periphery of the imaging surface.

In the embodiments of the invention, each of the light blocking portionsis formed to include an electrode light blocking portion that covers thecorresponding electrode and a pixel isolation and light blocking portionprotruding convexly from the upper surface of the electrode lightblocking portion. The pixel isolation and light blocking portions areformed in such a way that the width of the spaces between the pixelisolation and light blocking portions increases with distance from thecenter toward the periphery of the imaging surface.

According to the embodiments of the invention, a solid-state imagingdevice, an electronic apparatus, and a method for manufacturing the samecapable of improving the image quality of a captured image can beprovided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram showing the configuration of a camerain a first embodiment according to the invention;

FIG. 2 is a plan view schematically showing an overall configuration ofa solid-state imaging device in the first embodiment according to theinvention;

FIG. 3 shows a-key portion of the solid-state imaging device in thefirst embodiment according to the invention;

FIG. 4 shows another key portion of the solid-state imaging device inthe first embodiment according to the invention;

FIG. 5 shows another key portion of the solid-state imaging device inthe first embodiment according to the invention;

FIG. 6 shows a key portion formed in a step of a method formanufacturing the solid-state imaging device in the first embodimentaccording to the invention;

FIG. 7 shows the key portion formed in another step of the method formanufacturing the solid-state imaging device in the first embodimentaccording to the invention;

FIG. 8 shows the key portion formed in another step of the method formanufacturing the solid-state imaging device in the first embodimentaccording to the invention;

FIG. 9 shows the key portion formed in another step of the method formanufacturing the solid-state imaging device in the first embodimentaccording to the invention;

FIG. 10 shows a key portion of a solid-state imaging device in a secondembodiment according to the invention;

FIG. 11 shows another key portion of the solid-state imaging device inthe second embodiment according to the invention;

FIG. 12 shows another key portion of the solid-state imaging device inthe second embodiment according to the invention;

FIG. 13 shows a key portion of a solid-state imaging device in a thirdembodiment according to the invention;

FIG. 14 shows a key portion of a solid-state imaging device in a fourthembodiment according to the invention;

FIG. 15 shows a key portion formed in a step of a method formanufacturing the solid-state imaging device in the fourth embodimentaccording to the invention;

FIG. 16 shows the key portion formed in another step of the method formanufacturing the solid-state imaging device in the fourth embodimentaccording to the invention;

FIG. 17 shows the key portion formed in another step of the method formanufacturing the solid-state imaging device in the fourth embodimentaccording to the invention;

FIG. 18 shows a key portion of a solid-state imaging device in a fifthembodiment according to the invention;

FIG. 19 shows a key portion formed in a step of a method formanufacturing the solid-state imaging device in the fifth embodimentaccording to the invention;

FIG. 20 shows the key portion formed in another step of the method formanufacturing the solid-state imaging device in the fifth embodimentaccording to the invention;

FIG. 21 shows the key portion formed in another step of the method formanufacturing the solid-state imaging device in the fifth embodimentaccording to the invention;

FIG. 22 shows the key portion formed in another step of the method formanufacturing the solid-state imaging device in the fifth embodimentaccording to the invention;

FIG. 23 shows a portion where a color filter is formed on the uppersurface of a polysilicon film PL in the fourth and fifth embodimentsaccording to the invention;

FIG. 24 shows a key portion of a solid-state imaging device in a sixthembodiment according to the invention;

FIG. 25 shows a key portion formed in a step of a method formanufacturing the solid-state imaging device in the sixth embodimentaccording to the invention;

FIG. 26 shows the key portion formed in another step of the method formanufacturing the solid-state imaging device in the sixth embodimentaccording to the invention;

FIG. 27 shows the key portion formed in another step of the method formanufacturing the solid-state imaging device in the sixth embodimentaccording to the invention; and

FIG. 28 shows a key portion of a solid-state imaging device in a seventhembodiment according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the invention will be described below with reference tothe drawings.

The description will be made in the following order.

1. First embodiment (all pitches and light receiving area increase withdistance from center toward periphery)

2. Second embodiment (pitches at which pixel isolation and lightblocking portions are disposed increase with distance from center towardperiphery)

3. Third embodiment (the width of pixel isolation and light blockingportion decreases with distance from center toward periphery)

4. Fourth embodiment (color filter is formed as plano-convex lens whoselower side is convex surface)

5. Fifth embodiment (color filter is formed as light guide (air gap))

6. Sixth embodiment (color filter is formed as light guide (oxide film))

7. Seventh embodiment (the thickness of on-chip lens increases withdistance from center toward periphery)

8. Others

1. First Embodiment Device Configuration

(1) Overall Configuration of Camera

FIG. 1 is a configuration diagram showing the configuration of a camera200 in a first embodiment according to the invention.

As shown in FIG. 1, the camera 200 includes a solid-state imaging device1, an optical system 202, a drive circuit 203, and a signal processingcircuit 204.

The solid-state imaging device 1 captures the light (subject image) thatpasses through the optical system 202 and impinges on an imaging surfacePS, produces a signal charge, and outputs the signal charge as raw data.The configuration of the solid-state imaging device 1 will be describedlater in detail.

The optical system 202 includes an optical lens or any other suitablecomponent and focuses the subject image on the imaging surface PS of thesolid-state imaging device 1.

Specifically, a principal ray H1 exits through the optical system 202and impinges on a central portion of the imaging surface PS of thesolid-state imaging device 1 at right angles, as shown in FIG. 1. On theother hand, a principal ray H2 exits through the optical system 202 andimpinges on a peripheral portion of the imaging surface PS at an angleinclined to the direction perpendicular to the imaging surface PS. Sincethe exit pupil of the optical system 202 is positioned at a finitedistance, the inclination of the principal ray H2 directed toward theimaging surface PS of the solid-state imaging device 1 increases withdistance from the center toward the periphery.

The drive circuit 203 outputs a variety of drive signals to thesolid-state imaging device 1 and the signal processing circuit 204 todrive the solid-state imaging device 1 and the signal processing circuit204.

The signal processing circuit 204 performs signal processing on the rawdata outputted from the solid-state imaging device 1 to produce adigitized subject image.

(2) Overall Configuration of Solid-State Imaging Device

FIG. 2 is a plan view schematically showing an overall configuration ofthe solid-state imaging device 1 in the first embodiment according tothe invention.

As shown in FIG. 2, the solid-state imaging device 1 is, for example, aninterline CCD image sensor and captures a subject image on an imagingregion PA.

Photoelectric converters P, charge readout portions RO, and verticaltransfer registers VT are formed in the imaging region PA, as shown inFIG. 2.

A plurality of photoelectric converters P are provided in the imagingregion PA and arranged in the horizontal direction x and the verticaldirection y to form a matrix, as shown in FIG. 2. That is, a pluralityof pixels that captures a subject image are arranged in a matrix. Anelement isolator SS is provided around each of the plurality ofphotoelectric converters P so that the photoelectric converter P isisolated from the others. Each of the photoelectric converters P hasalight receiving surface JS that receives subject image light andperforms photoelectric conversion to produce a signal charge.

A plurality of charge readout portions RO are provided in the imagingregion PA in correspondence with the plurality of photoelectricconverters P, as shown in FIG. 2. Each of the charge readout portions ROreads the signal charge produced by the corresponding photoelectricconverter P and outputs it to the corresponding vertical transferregister VT.

The vertical transfer registers VT extend in the imaging region PA inthe vertical direction y in correspondence with the plurality ofphotoelectric converters P arranged in the vertical direction y, asshown in FIG. 2. Further, the vertical transfer registers VT aredisposed between the columns formed of the plurality of photoelectricconverters P arranged in the vertical direction y. The plurality ofvertical transfer registers VT, which are provided in the imaging regionPA, are arranged in the horizontal direction x in correspondence withthe plurality of photoelectric converters P arranged in the horizontaldirection x. Each of the vertical transfer registers VT is what iscalled a vertical transfer CCD, reads signal charges from thecorresponding photoelectric converters P through the correspondingcharge readout portions RO, and sequentially transfers the signalcharges in the vertical direction y. Each of the vertical transferregisters VT, which will be described later in detail, has a pluralityof transfer electrodes (not shown) arranged in the vertical direction y,and the transfer electrodes arranged in the vertical directionsequentially receive four-phase drive pulse signals to transfer thesignal charges.

A horizontal transfer register HT is disposed in a lower end portion ofthe imaging region PA, as shown in FIG. 2. The horizontal transferregister HT extends in the horizontal direction x and sequentiallytransfers in the horizontal direction x the signal charges transferredin the vertical direction y by each of the plurality of the verticaltransfer registers VT. That is, the horizontal transfer register HT iswhat is called a horizontal transfer CCD and driven, for example, by atwo-phase drive pulse signal to transfer the signal charges having beentransferred for each horizontal line (a row of pixels).

An output section OUT is formed at the left end of the horizontaltransfer register HT, as shown in FIG. 2. The output section OUTconverts the signal charges having been transferred in the horizontaldirection by the horizontal transfer register HT into voltages, andoutputs the voltages as an analog image signal.

The imaging region PA described above corresponds to the imaging surfacePS shown in FIG. 1.

(3) Detailed Configuration of Solid-State Imaging Device

The configuration of the solid-state imaging device 1 will be describedin detail.

FIGS. 3, 4, and 5 show key portions of the solid-state imaging device 1in the first embodiment according to the invention.

FIGS. 3 and 4 are cross-sectional views, taken along the X direction, ofkey portions of the pixels arranged in the imaging region. FIG. 3 showsa central portion of the imaging region PA, and FIG. 4 shows aperipheral portion of the imaging region PA.

FIG. 5 is an enlarged top view showing a key portion of the imagingregion PA of the solid-state imaging device 1. FIG. 5 shows a portionaround the center Cy in the vertical direction y and the center Cx inthe horizontal direction x in the imaging region PA, the portionincludes a plurality of photoelectric converters P arranged in thehorizontal direction x. Although not shown in FIG. 5, a portionincluding a plurality of photoelectric converters P arranged in thevertical direction y is configured in the same manner.

The solid-state imaging device 1 includes a substrate 101, as shown inFIGS. 3 and 4. The substrate 101 is, for example, an n-type siliconsemiconductor substrate, and photodiodes 21, charge readout channelregions 22, charge transfer channel regions 23, and channel stopperregions 24 are provided in the substrate 101.

Transfer electrodes 31, light blocking portions 40, color filters 51,and on-chip lenses 61 are provided over the surface of the substrate101, as shown in FIGS. 3 and 4.

The above components, which form the solid-state imaging device 1, willbe described in order.

The photodiodes 21 are provided in the substrate 101 in correspondencewith the photoelectric converters P, as shown in. FIGS. 3 and 4. Each ofthe photodiodes 21 receives light incident on the light receivingsurface JS and performs photoelectric conversion to produce a signalcharge.

Specifically, the photodiodes 21 are provided in the substrate 101 butlocated close to the surface thereof. Although not shown, each of thephotodiodes 21 includes, for example, a p-type semiconductor well region(p) (not shown) formed in the substrate 101, and an n-type semiconductorregion (n) (not shown) and a p-type semiconductor region (p⁺) (notshown) are subsequently formed on the p-type semiconductor well region(p). The n-type semiconductor region (n) functions as a signal chargeaccumulation region, and the p-type semiconductor region (p⁺) functionsas a hole accumulation region and suppresses dark current in the n-typesemiconductor region (n), which is the signal charge accumulationregion.

The color filters 51 and the on-chip lenses 61 are disposed above therespective photodiodes 21, as shown in FIGS. 3 and 4. The lightreceiving surface JS of each of the photodiodes 21 therefore receiveslight sequentially passing through the corresponding on-chip lens 61 andcolor filter 51.

The principal ray H1 is incident along the depth direction z, which isperpendicular to the light receiving surface JS, on the central portionof the imaging region PA (central portion of the angle of view), asshown in FIG. 3. The photodiodes 21 in the central portion receive theprincipal ray H1 incident along the depth direction z and produce signalcharges.

On the other hand, the principal ray H2 is incident along a directioninclined to the depth direction z, which is perpendicular to the lightreceiving surface JS, on the peripheral portion of the imaging region PA(the end of the angle of view), as shown in FIG. 4. That is, theincident principal ray H2 is not perpendicular to the light receivingsurface JS but inclined thereto. The photodiodes 21 in the peripheralportion receive the principal ray H2 incident along the inclineddirection and produce signal charges.

In the present embodiment, a plurality of photoelectric converters P arearranged at first pitches P1 in the imaging plane (xy plane), as shownin FIG. 5. The plurality of photoelectric converters P are disposed atthe first pitches P1, which increase with distance from the center Cxtoward the periphery in the horizontal direction x in the imaging plane.

Specifically, the plurality of disposed photoelectric converters Psatisfy the following equation (1) when the first pitches P1 are calledP11, P12, P13, P14, . . . counted from the center Cx toward theperiphery in the horizontal direction x, as shown in FIG. 5.P11<P12<P13<P14<  (1)

That is, the pitch P11 between the photoelectric converters P in thefirst and second pixels counted from the center Cx toward the peripheryin the horizontal direction x of the imaging region PA is smaller thanthe pitch P12 between the photoelectric converters P in the second andthird pixels. Further, the pitch P12 between the photoelectricconverters P in the second and third pixels is smaller than the pitchP13 between the photoelectric converters P in the third and fourthpixels.

In addition to the above, the plurality of photoelectric converters Pareformed in such a way that the area of the light receiving surfaces JSincreases with distance from the center Cx toward the periphery in thehorizontal direction x.

That is, the area of the light receiving surfaces JS of thephotoelectric converter P in the first pixel counted from the center Cxtoward the periphery in the horizontal direction x of the imaging regionPA is smaller than the area of the light receiving surfaces JS of thephotoelectric converter. P in the second pixel. Further, the area of thelight receiving surface JS of the photoelectric converter P in thesecond pixel is smaller than the area of the light receiving surface JSof the photoelectric converter P in the third pixel.

The photodiodes 21 formed in correspondence with the plurality ofphotoelectric converters P are therefore formed in such a way that thewidth of a photodiode 21 increases with distance from the center towardthe periphery of the imaging region PA, as seen by comparing FIG. 3 withFIG. 4.

The first pitch P1 described above is the distance between the centersof the plurality of photoelectric converters P arranged in thehorizontal direction x. The plurality of photoelectric converters Parranged in the vertical direction y are formed in the same manner asthe plurality of photoelectric converters P arranged in the horizontaldirection x.

The charge readout channel regions 22 are provided in correspondencewith the charge readout portions RO and configured to read signalcharges produced in the photodiodes 21, as shown in FIGS. 3 and 4.

Specifically, the charge readout channel regions 22 are provided in thesubstrate 101 but located close to the surface thereof and adjacent tothe respective photodiodes 21, as shown in FIGS. 3 and 4.

In the present embodiment, the charge readout channel regions 22 aredisposed on the left of the respective photodiodes 21 in the horizontaldirection x. For example, each of the charge readout channel regions 22is formed as a p-type semiconductor region.

The charge transfer channel regions 23 are provided in correspondencewith the vertical transfer registers VT, as shown in FIGS. 3 and 4, andconfigured to transfer the signal charges read from the respectivephotodiodes 21 through the respective charge readout portions RO.

Specifically, the charge transfer channel regions 23 are provided in thesubstrate 101 but located close to the surface thereof and adjacent tothe respective charge readout channel regions 22, as shown in FIGS. 3and 4.

In the present embodiment, the charge transfer channel regions 23 aredisposed on the left of the respective charge readout channel regions 22in the horizontal direction x. For example, each of the charge transferchannel regions 23 is formed by providing an n-type semiconductor region(n) (not shown) on a p-type semiconductor well region (p) (not shown) inthe substrate 101.

The channel stopper regions 24 are provided in correspondence with theelement isolators SS, as shown in FIGS. 3 and 4.

Specifically, the channel stopper regions 24 are provided in thesubstrate 101 but located close to the surface thereof, as shown inFIGS. 3 and 4.

In the present embodiment, each of the channel stopper regions 24 isprovided, in the horizontal direction x, on the left of thecorresponding charge readout channel region 23 and between the chargereadout channel region 22 and the photodiode 21 disposed in the adjacentcolumn, as shown in FIGS. 3 and 4.

In the vertical direction y, since the element isolators SS are providedto separate the plurality of photoelectric converters P as shown in FIG.2, the channel stopper regions described above are provided between anypair of two photodiodes 21 arranged in the vertical direction y, but nocross section of this portion is shown.

Each of the channel stopper regions 24 described above is, for example,formed by providing a p-type semiconductor region (p+) (not shown) on ap-type semiconductor well region (p) (not shown) in the substrate 101,and forms a potential barrier to prevent any signal charge from flowingin and out.

The transfer electrodes 31 are provided above the substrate 101 incorrespondence with the vertical transfer registers VT, as shown inFIGS. 3 and 4, and configured to function as vertical transferelectrodes that transfer the read signal charges in the verticaldirection y. The transfer electrodes 31 are also disposed incorrespondence with the charge readout portions RO and configured tofunction as charge readout electrodes that read signal charges producedby the photodiodes 21.

Specifically, each of the transfer electrodes 31 is disposed on theupper surface of the substrate 101 and faces the corresponding chargereadout channel region 22 and charge transfer channel region 23 via agate insulating film Gx, as shown in FIGS. 3 and 4.

For example, each of the transfer electrodes 31 is made of polysiliconor any other suitable conductor and provided on the gate insulating filmGx formed of, for example, a silicon oxide film.

The transfer electrodes 31 are provided between the plurality ofphotoelectric converters P, as shown in FIGS. 3 and 4. Although notshown, each of the plurality of transfer electrodes 31 includes aportion extending in the horizontal direction x on the upper surface ofthe substrate 101, and the plurality of extending portions areelectrically connected in the horizontal direction x.

In addition to the transfer electrodes 31 shown in FIGS. 3 and 4, othertransfer electrodes (not shown) are provided between the plurality ofphotoelectric converters P arranged in the vertical direction y. The twotypes of transfer electrode are alternately provided in the verticaldirection.

The light blocking portions 40 are provided above the substrate 101, asshown in FIGS. 3 and 4.

Each of the light blocking portions 40 includes an electrode lightblocking layer 41 and a pixel isolation and light blocking layer 42, asshown in FIGS. 3 and 4.

In each of the light blocking portions 40, the electrode light blockinglayer 41 is formed on the surface of the substrate 101 and above thecorresponding charge readout channel region 22 and charge transferchannel region 23, as shown in FIGS. 3 and 4. The electrode lightblocking layer is provided also to cover the corresponding transferelectrode 31 via an insulating film Sz. The insulating film Sz is, forexample, a PSG film, and the electrode light blocking layer 41 is madeof a light-blocking metallic material that blocks light, such astungsten and aluminum.

In each of the light blocking portions 40, the pixel isolation and lightblocking layer 42 protrudes from the upper surface of the electrodelight blocking layer 41, as shown in FIGS. 3 and 4. For example, thepixel isolation and light blocking layer 42 is made of a metallicmaterial, such as tungsten and aluminum, like the electrode lightblocking layer 41.

In the present embodiment, the light blocking portions are providedbetween the plurality of photoelectric converters P arranged in theimaging region PA, as shown in FIG. 5. In FIG. 5, the light blockingportions 40 are disposed between the plurality of photoelectricconverters P arranged in the horizontal direction x and between thephotoelectric converters P arranged in the vertical direction y. Thatis, the plurality of light blocking portions 40 are interposed betweenthe photoelectric converters. P in the horizontal direction x. Further,the plurality of light blocking portions 40 are interposed between thephotoelectric converters P in the vertical direction y.

In each of the plurality of light blocking portions 40, the electrodelight blocking layer 41 includes portions 41 x extending in thehorizontal direction x and portions 41 y extending in the verticaldirection y (both the portions 41 x and 41 y are electrode lightblocking portions), and the portions 41 x and 41 y are integrated witheach other, as shown in FIG. 5.

A plurality of portions 41 y, each of which extends in the verticaldirection y in the corresponding electrode light blocking layer 41, arearranged at second pitches P2 in the horizontal direction x of theimaging region PA, as shown in FIG. 5. The portions 41 y are formed insuch a way that the second pitch P2 increases with distance from thecenter Cx toward the periphery in the horizontal direction x in theimaging region PA.

Specifically, the disposed portions 41 y satisfy the following equation(2) when the second pitches P2 are called P21, P22, P23, P24, . . .counted from the center Cx toward the periphery in the horizontaldirection x, as shown in FIG. 5.P21<P22<P23<P24<  (2)

In the present embodiment, the second pitches P2 and the first pitchesP1, at which the plurality of photoelectric converters P are arranged,increase at the same rate, as shown in FIG. 5.

The portions 41 y extending in the vertical direction y in therespective electrode light blocking layers 41 are formed in such a waythat the widths H20, H21, H22, H23, H24, . . . defined in the horizontaldirection x have the same value, as shown in FIG. 5.

The second pitches P2 described above show the distances between thecenters of the widths H20, H21, H22, H23, H24, . . . defined in thehorizontal direction x based on the portions 41 y extending in thevertical direction y in the respective electrode light blocking layers41. The portions 41 x extending in the horizontal direction x in therespective electrode light blocking layers 41 are provided in the samemanner as the portions 41 y extending in the vertical direction y in therespective electrode light blocking layers 41.

On the other hand, in each of the plurality of light blocking portions40, the pixel isolation and light blocking layer 42 includes portions 42x extending in the horizontal direction x and portions 42 y extending inthe vertical direction y (both the portions 42 x and 42 y are pixelisolation and light blocking portions), and the portions 42 x and 42 yare integrated with each other, as shown in FIG. 5.

A plurality of portions 42 y, each of which extends in the verticaldirection y in the corresponding pixel isolation and light blockinglayer 42, are arranged at third pitches P3 in the horizontal direction xof the imaging region PA, as shown in FIG. 5. The portions 42 y areformed in such a way that the third pitch P3 increases with distancefrom the center Cx toward the periphery in the horizontal direction x inthe imaging region PA.

Specifically, the disposed portions 42 y satisfy the following equation(3) when the third pitches P3 are called P31, P32, P33, P34, . . .counted from the center Cx toward the periphery in the horizontaldirection x, as shown in FIG. 5.P31<P32<P33<P34<  (3)

In the present embodiment, the third pitches P3 and the second pitchesP2, at which the portions extending in the vertical direction y aredisposed in the pixel isolation and light blocking layer 42, increase atthe same rate, as shown in FIG. 5. That is, the first pitch P1, thesecond pitch P2, and the third pitch P3 described above increase at thesame rate across the area from the center Cx to the periphery of theimaging region.

The portions 42 y extending in the vertical direction y in therespective pixel isolation and light blocking layers 42 are formed insuch a way that the widths H30, H31, H32, H33, H34, . . . defined in thehorizontal direction x have the same value, as shown in FIG. 5.

As a result, in the present embodiment, the widths G31, G32, G33, G34, .. . of the spaces between the portions 42 y extending in the verticaldirection y in the respective pixel isolation and light blocking layers42 satisfy the following equation (4). That is, the portions 42 y widenwith distance from the center Cx toward the periphery in the horizontaldirection x in the imaging region PA.G31<G32<G33<G34<  (4)

The third pitches P3 described above show the distances between thecenters of the widths H30, H31, H32, H33, H34, . . . defined in thehorizontal direction x based on the portions 42 y extending in thevertical direction y in the respective pixel isolation and lightblocking layers 42. The portions 42 x extending in the horizontaldirection x in the respective pixel isolation and light blocking layers42 are also provided in the same manner. That is, the pixel isolationand light blocking layers 42 are arranged in a grid-like matrix formedof partitioned unit cells, and the area of the partitioned regionsincreases from the center toward the periphery of the imaging region PA.

More specifically, the light blocking portions are formed in such a waythat they satisfy the relationship shown in a lower part of FIG. 5. Thelight blocking portions are formed by setting the value of a factor “a”to satisfy the equation (5) below. It is noted that the factor “a” isset to satisfy a>1.

$\begin{matrix}{\frac{b}{2} = {x + ( {x + a^{1}} ) + ( {x + a^{2}} ) + \ldots + ( {x + a^{({\frac{n}{2} - 1})}} )}} & (5)\end{matrix}$

The variables in the above equation mean as follows:

n: the number of effective pixels in the horizontal direction (verticaldirection)

x: the size of the pixel at the center of the angle of view (referencewidth) (nm)

a: the amount of shift (nm) (a>1)

b: the horizontal (vertical) dimension of the effective pixel region(nm)

In FIG. 5, the term “sum” represents the total distance (nm) from thecenter of the angle of view to the end thereof.

That is, the electrode light blocking layers 41 and pixel isolation andlight blocking layers 42 are formed in such a way that whenever thepixel position shifts toward the periphery, the amount of shift[a^((n/2−1))] is added to the distance (x) between the center Cx in thehorizontal direction x of the imaging region PA and the portion adjacentto the center.

The color filters 51 are provided above the substrate 101, as shown inFIGS. 3 and 4.

Specifically, each of the color filters 51 is formed above thecorresponding photodiode 21 and electrode light blocking layer 41 viapassivation films Es.

In the present embodiment, the color filters 51 are formed between thepixel isolation and light blocking layers 42, as shown in FIGS. 3 and 4.That is, the color filters 51 are buried in the portions partitioned bythe pixel isolation and light blocking layers 42.

Each of the color filters 51 colors the incident light and outputs ittoward the corresponding light receiving surface JS. For example, eachof the color filters 51 is made of a photosensitive resin containing acoloring agent. Although not shown, the color filters 51 are formed ofthree primary color filters, green filters, red filters, and bluefilters. The three primary color filters are disposed in the imagingregion PA shown in FIG. 2 in correspondence with the photoelectricconverters P, for example, in the Bayer layout.

The on-chip lenses 61 are provided above the substrate 101 and on thecolor filters 51, as shown in FIGS. 3 and 4.

In the present embodiment, each of the on-chip lenses 61 is a convexlens whose central portion is thicker than the periphery in thedirection from the light receiving surface JS of the correspondingphotodiode 21 toward the corresponding color filter 51, and focuses theincident light on the light receiving surface JS. For example, each ofthe on-chip lenses 61 has a circular shape in a plan view. The lightfocused by the on-chip lens 61 therefore passes through the color filter51 and is received by the light receiving surface JS of thecorresponding photodiode 21.

As described above, in the present embodiment, the photodiodes 21 areformed in such a way that those in the central portion of the imagingregion PA are wider than those in the peripheral portion thereof, asseen by comparing FIG. 3 with FIG. 4. Similarly, the on-chip lenses 61are formed in such a way that the width and hence the area thereofincrease with distance from the center toward the periphery of theimaging region PA.

[Manufacturing Method]

A method for manufacturing the above solid-state imaging device 1 willbe described below.

FIGS. 6, 7, 8, and 9 show a key portion formed in the steps of themethod for manufacturing the solid-state imaging device 1 in the firstembodiment according to the invention. FIGS. 6, 7, 8, and 9 show thesame cross section as that shown in FIG. 3.

In the following description, the step of forming the pixel isolationand light blocking layers 42 will primarily be described.

(1) Formation of Planarization Film FT

A planarization film FT is first formed, as shown in FIG. 6.

Before the formation of the planarization film FT, the photodiodes 21,the charge readout channel regions 22, the charge transfer channelregions 23, and the channel stopper regions 24 are provided in thesubstrate 101, as shown in FIG. 6. For example, ion implantation is usedto introduce impurities into the substrate 101 to form the componentsdescribed above. Thereafter, thermal oxidation is, for example, used toform a silicon oxide film over the substrate 101. The gate insulatingfilm Gx is thus formed.

The transfer electrodes 31 and other components are formed on thesurface of the substrate 101, as shown in FIG. 6. For example, CVD isused to form a polysilicon film (not shown), and then photolithographyis used to pattern the polysilicon film. The transfer electrodes 31 arethus formed. The insulating film Sz, for example, a PSG film, is formedto cover the transfer electrodes 31. Thereafter, sputtering is, forexample, used to form a tungsten film, and then photolithography is usedto pattern the tungsten film. The electrode light blocking layers 41 arethus formed. The passivation film Es is then formed to cover thephotodiodes 21 and the transfer electrodes 31. The passivation film Esfunctions as an etching stopper when an etchant is used to remove theplanarization film FT in a later process. For example, the passivationfilm Es is formed of a P—SiN film.

Thereafter, the planarization film FT is formed to cover the passivationfilm Es, as shown in FIG. 6.

In the present embodiment, SOG or any other suitable resin is applied toform a film, and then CMP or any other suitable planarization process iscarried out to form the planarization film FT. The planarization film FTmay alternatively be formed of a TEOS-based SiO₂/BPSG film or anSiO₂-based CVD film formed by using biased high-density plasma.

(2) Formation of Grooves K1

Grooves K1 are then formed, as shown in FIG. 7.

In the present embodiment, the grooves K1 are formed in the portions ofthe planarization film FT where the pixel isolation and light blockinglayers 42 described above are formed (see FIG. 3, for example), as shownin FIG. 7.

Specifically, photolithography and dry etching are used to form thegrooves K1, each of which having a width of 1 μm or smaller, so thatpart of the upper surfaces of the electrode light blocking layers 41 isexposed.

(3) Formation of Pixel Isolation and Light Blocking Layers 42

The pixel isolation and light blocking layers 42 are then formed, asshown in FIG. 8.

In the present embodiment, the grooves K1 formed as described above arefilled with a light-blocking material, and then the planarization filmFT is removed to form the pixel isolation and light blocking layers 42,as shown in FIG. 8.

For example, CVD or sputtering is used to form a film by filling thegrooves K1 with a metallic material, and then the resultant structure isetched back to remove the metal film (not shown) on the planarizationfilm FT. Thereafter, for example, HF-based etching is carried out toremove the planarization film FT.

(4) Formation of Color Filters 51

The color filters 51 are then formed, as shown in FIG. 9.

In the present embodiment, the color filters 51 are formed by fillingthe spaces between the pixel isolation and light blocking layers 42, asshown in FIG. 9.

Specifically, the color filters 51 are formed by applying aphotosensitive resin material containing a coloring agent.

The other portions are then provided. The solid-state imaging device 1is thus completed.

[Brief]

As described above, in the present embodiment, the photodiodes 21 areformed in such a way that the first pitch P1 increases and the area ofthe light receiving surfaces JS increases with distance from the centertoward the periphery of the imaging region PA. The electrode lightblocking layers 41 are formed to include portions in which the secondpitch P2 increases with distance from the center toward the periphery ofthe imaging region PA. Further, the pixel isolation and light blockinglayers 42 are formed to include portions in which the third pitch P3increases with distance from the center toward the periphery of theimaging region PA. In the present embodiment, the first pitch P1, thesecond pitch P2, and the third pitch P3 increase at the same rate overthe area from the center to the periphery of the imaging region PA. Thatis, the pixel isolation and light blocking layers 42 are formed toinclude portions in which the widths G31, G32, G33, G34, . . . of thespaces between the pixel isolation and light blocking layers 42 increasewith distance from the center toward the periphery of the imaging regionPA.

As described above, at the end of the angle of view (the periphery ofthe imaging region PA), since the principal ray H2 is incident at alarge angle, the light receiving surface JS of each of the photodiodes21 in that region does not readily receive the incident light, acaptured image suffers from shading in some cases. When the inclinedincident principal ray H2 enters the photodiode 21 in the adjacentpixel, color mixing occurs in a captured image in some cases (see FIG.4).

In the present embodiment, however, the area of the light receivingsurface JS at the end of the angle of view (the periphery of the imagingregion PA) is larger than that at the center of the angle of view (thecenter of the imaging region PA). Further, the distance between theplurality of light blocking portions 40 is larger at the periphery ofthe imaging region PA than at the center of thereof. Moreover, theon-chip lenses 61 are formed in such a way that the area thereofincreases with distance from the center toward the periphery of theimaging region PA. It is therefore possible to improve the sensitivityat the end of the angle of view without compromising the sensitivity atthe center of the angle of view, and also possible to suppress shadingin a captured image. Further, since the inclined principal ray directedtoward the photodiode 21 in the pixel adjacent to a pixel in question isblocked by the corresponding pixel isolation and light blocking layer42, color mixing can be suppressed in a captured image.

In the present embodiment, the image quality of a captured image canthus be improved.

The present embodiment has been presented with reference to the casewhere the first to third pitches P1, P2, and P3 and the area of thelight receiving surfaces JS increase with distance from the centertoward the periphery of the imaging region PA in both the horizontaldirection x and the vertical direction y, but the present embodiment isnot limited thereto. The present embodiment may be configured in such away that the first to third pitches P1, P2, and P3 and the area of thelight receiving surfaces JS increase only in the horizontal direction xor the vertical direction y.

2. Second Embodiment Device Configuration and Others

FIGS. 10, 11, and 12 show key portions of a solid-state imaging device 1b in a second embodiment according to the invention.

FIGS. 10 and 11 are cross-sectional views, taken along the X direction,of key portions of the pixels arranged in the imaging region PA shown inFIG. 2. FIG. 10 shows a central portion of the imaging region PA, andFIG. 11 shows a peripheral portion of the imaging region PA.

FIG. 12 is an enlarged top view showing a key portion of the imagingregion PA of the solid-state imaging device 1 b.

FIG. 12 shows a portion around the center Cy in the vertical direction yand the center Cx in the horizontal direction x in the imaging area PA,and the portion includes a plurality of photoelectric converters Parranged in the horizontal direction x. Although not shown in FIG. 12, aportion including a plurality of photoelectric converters P arranged inthe vertical direction y is configured in the same manner.

As shown in FIGS. 10, 11, and 12, the solid-state imaging device 1 b inthe present embodiment differs from the solid-state imaging device 1 inthe first embodiment in terms of the arrangement of the photoelectricconverters P, the electrode light blocking layers 41, and the pixelisolation and light blocking layers 42. The present embodiment is thesame as the first embodiment except the point described above and pointsassociated therewith. No description of the redundant portions will bemade.

The photoelectric converters P are arranged at first pitches P1 in aplurality of imaging planes (xy plane), as shown in FIG. 12. Theplurality of photoelectric converters P are disposed at the firstpitches P1, which have the same value over the imaging region PA fromthe center Cx to the periphery thereof.

Specifically, the plurality of disposed photoelectric converters Psatisfy the following equation (1b) when the first pitches P1 are calledP11, P12, P13, P14, . . . counted from the center Cx toward theperiphery in the horizontal direction x, as shown in FIG. 12.P11=P12=P13=P14=  (1b)

In addition to the above, the plurality of photoelectric converters Pare formed in such a way that the areas of the light receiving surfacesJS are the same over the region from the center Cx toward the peripheryin the horizontal direction x.

The photodiodes 21 formed in correspondence with the plurality ofphotoelectric converters P are therefore formed in such a way that thewidths of the photodiodes 21 in the central portion of the imagingregion PA are the same as those of the photodiodes 21 in the peripheralportion, as shown FIGS. 10 and 11.

The plurality of photoelectric converters P arranged in the verticaldirection y are formed in the same manner described above. That is, theplurality of photoelectric converters P arranged in the verticaldirection y are formed in such a way that the areas of the lightreceiving surfaces JS are the same over the region from the center Cytoward the periphery, like the plurality of photoelectric converters Parranged in the horizontal direction x.

In each of the light blocking portions 40, the electrode light blockinglayer 41 includes portions 41 x extending in the horizontal direction xand portions 41 y extending in the vertical direction y, as shown inFIG. 12. A plurality of portions 41 y, each of which extends in thevertical direction y in the corresponding electrode light blocking layer41, are arranged at second pitches P2 in the horizontal direction x ofthe imaging region PA, as shown in FIG. 12.

The portions 41 y are disposed in such a way that the second pitches P2have the same value over the imaging region PA from the center Cx towardthe periphery thereof.

Specifically, the disposed portions 41 y satisfy the following equation(2b) when the second pitches P2 are called P21, P22, P23, P24, . . .counted from the center Cx toward the periphery in the horizontaldirection x, as shown in FIG. 12.P21=P22=P23=P24=  (2b)

In the present embodiment, the second pitches P2 are equal to the firstpitches P1, at which the plurality of photoelectric converters P aredisposed, and have a fixed value, as shown in FIG. 12.

The electrode light blocking layers 41 are therefore formed in such away that the distances therebetween in the central portion of theimaging region PA are the same as those in the peripheral portion, asshown in the cross-sectional views of FIGS. 10 and 11.

The portions 41 x extending in the horizontal direction x in therespective electrode light blocking layers 41 are provided in the samemanner as the portions 41 y extending in the vertical direction y in therespective electrode light blocking layers 41.

Further, in each of the plurality of light blocking portions 40, thepixel isolation and light blocking layer 42 includes portion 42 xextending in the horizontal direction x and portions 42 y extending inthe vertical direction y, as shown in FIG. 12. A plurality of portions42 y, each of which extends in the vertical direction y in thecorresponding pixel isolation and light blocking layer 42, are arrangedat third pitches P3 in the horizontal direction x of the imaging regionPA, as shown in FIG. 12.

As shown in FIG. 12, the portions 42 y are formed in such away that thethird pitch P3 increases with distance from the center Cx toward theperiphery in the horizontal direction x in the imaging region PA, as inthe first embodiment.

Specifically, the disposed portions 42 y satisfy the following equation(3b) when the third pitches P3 are called P31, P32, P33, P34, . . .counted from the center Cx toward the periphery in the horizontaldirection x, as shown in FIG. 12.P31<P32<P33<P34<  (3b)

As a result, in the present embodiment, the widths G31, G32, G33, G34, .. . of the spaces between the portions 42 y extending in the verticaldirection y in the respective pixel isolation and light blocking layers42 satisfy the following equation (4b). That is, the portions 42 y widenwith distance from the center Cx toward the periphery in the horizontaldirection x in the imaging region PA.G31<G32<G33<G34<  (4b)

The pixel isolation and light blocking layers 42 are therefore formed insuch a way that the distances therebetween increase with distance fromthe center toward the periphery of the imaging region PA, as shown inthe cross-sectional views of FIGS. 10 and 11.

More specifically, the third pitches P3 (P31, P32, P33, P34, . . . ) aredefined as shown in a lower right part of FIG. 12. The pixel isolationand light blocking layers 42 are formed in such a way that a factor “a”satisfies the equation (5b) below. It is noted that the factor “a” isset to satisfy a>1.

$\begin{matrix}{{( {x - \frac{y - z}{2}} ) + ( {x - \frac{y - z}{2} + a^{1}} ) + ( {x - \frac{y - z}{2} + a^{2}} ) + \ldots + ( {x - \frac{y - z}{2} + a^{({\frac{n}{2} - 1})}} )} \leq \frac{{nx} + y - z}{2}} & ( {5b} )\end{matrix}$

The variables in the above equation mean as follows:

n: the number of effective pixels in the horizontal direction (verticaldirection)

x: the size of a pixel (reference width) (nm)

y: the width of an electrode light blocking layer (nm)

a: the amount of shift (nm) (a>1)

z: the width of a pixel isolation and light blocking layer (nm)

In FIG. 12, the term “sum” represents the total distance (nm) from thecenter of the angle of view to the end thereof.

The portions 42 x extending in the horizontal direction x in therespective pixel isolation and light blocking layers 42 are provided inthe same manner.

[Brief]

As described above, in the present embodiment, the pixel isolation andlight blocking layers 42 are formed to include portions in which thethird pitch P3 increases with distance from the center toward theperiphery of the imaging region PA. That is, the pixel isolation andlight blocking layers 42 are formed to include portions in which thewidths G31, G32, G33, G34, . . . of the spaces between the pixelisolation and light blocking layers 42 increase with distance from thecenter toward the periphery of the imaging region PA.

It is therefore possible in the present embodiment to improve thesensitivity at the end of the angle of view without compromising thesensitivity at the center of the angle of view, and also possible tosuppress shading in a captured image. Further, since the inclinedprincipal ray directed toward the photodiode 21 in the pixel adjacent toa pixel in question is blocked by the corresponding pixel isolation andlight blocking layer 42, color mixing can be suppressed in a capturedimage.

In the present embodiment, the image quality of a captured image canthus be improved.

Further, the present embodiment has been presented with reference to thecase where the third pitch P3 increases in both the horizontal directionx and the vertical direction y with distance from the center toward theperiphery of the imaging region PA, but the present embodiment is notlimited thereto. The present embodiment may be configured in such a waythat the third pitch P3 increases only in the horizontal direction x orthe vertical direction y.

3. Third Embodiment Device Configuration and Others

FIG. 13 shows a key portion of a solid-state imaging device 1 c in athird embodiment according to the invention.

FIG. 13 is an enlarged top view showing a key portion of the imagingregion PA of the solid-state imaging device 1 c.

FIG. 13 shows a portion around the center Cy in the vertical direction yand the center Cx in the horizontal direction x in the imaging regionPA, and the portion includes a plurality of photoelectric converters Parranged in the horizontal direction x.

As shown in FIG. 13, the solid-state imaging device 1 c in the presentembodiment differs from the solid-state imaging device 1 b in the secondembodiment in terms of the arrangement of the pixel isolation and lightblocking layers 42. The present embodiment is the same as the secondembodiment except the point described above and points associatedtherewith. No description of the redundant portions will be made.

Each of the pixel isolation and light blocking layers 42 includesportion 42 x extending in the horizontal direction x and portions 42 yextending in the vertical direction y, as shown in FIG. 13. A pluralityof portions 42 y, each of which extends in the vertical direction y inthe corresponding pixel isolation and light blocking layer 42, arearranged at third pitches P3 in the horizontal direction x of theimaging region PA, as shown in FIG. 13.

In the present embodiment, the third pitches P3 are set to be the sameas the first pitches P1 of the photoelectric converters P and the secondpitches P2 of the electrode light blocking layers 41.

The portions 42 y extending in the vertical direction y are, however,formed in the respective pixel isolation and light blocking layers 42 insuch a way that the width of the portions 42 y successively decreaseswith distance from the center Cy to the periphery of the imaging regionPA.

Specifically, the disposed portions 42 y satisfy the following equation(c1) when the widths are called H30, H31, H32, H33, H34, . . . countedfrom the center Cx toward the periphery in the horizontal direction x,as shown in FIG. 13.H30>H31>H32>H33>H34>  (c1)

As a result, in the present embodiment, the widths G31, G32, G33, G34, .. . of the spaces between the portions 42 y extending in the verticaldirection y in the respective pixel isolation and light blocking layers42 satisfy the following equation (c2). That is, the portions 42 y widenwith distance from the center Cx toward the periphery in the horizontaldirection x in the imaging region PA.G31<G32<G33<G34<  (c2)

The portions 42 x extending in the horizontal direction x in therespective pixel isolation and light blocking layers 42 are provided inthe same manner.

[Brief]

As described above, in the present embodiment, the pixel isolation andlight blocking layers 42 are formed to include portions whose widthdecreases with distance from the center Cx toward the periphery of theimaging region PA. That is, the pixel isolation and light blockinglayers 42 are formed to include portions in which the widths G31, G32,G33, G34, . . . of the spaces between the pixel isolation and lightblocking layers 42 increase with distance from the center toward theperiphery of the imaging region PA.

It is therefore possible in the present embodiment to improve thesensitivity at the end of the angle of view without compromising thesensitivity at the center of the angle of view, and also possible tosuppress shading in a captured image. Further, since the inclinedprincipal ray directed toward the photodiode 21 in the pixel adjacent toa pixel in question is blocked by the corresponding pixel isolation andlight blocking layer 42, color mixing can be suppressed in a capturedimage.

In the present embodiment, the image quality of a captured image canthus be improved.

Further, the present embodiment has been presented with reference to thecase where the widths of the pixel isolation and light blocking layers42 in both the horizontal direction x and the vertical direction y varywith the position in the imaging region PA, but the present embodimentis not limited thereto. The present embodiment may be configured in sucha way that one of the widths of the pixel isolation and light blockinglayers 42 in the horizontal direction x and the vertical direction y isfixed, as in the second embodiment.

4. Fourth Embodiment Device Configuration

FIG. 14 shows a key portion of a solid-state imaging device 1 d in afourth embodiment according to the invention.

FIG. 14 is a cross-sectional view, taken along the X direction, of a keyportion of the pixels arranged in the imaging region PA shown in FIG. 2.FIG. 14 shows a central portion of the imaging region PA.

As shown in FIG. 14, the solid-state imaging device 1 d in the presentembodiment differs from the solid-state imaging device 1 a in the firstembodiment in terms of the shape of color filters 51 d. Transparentlayers 50 are further provided. The present embodiment is the same asthe first embodiment except the point described above and pointsassociated therewith. No description of the redundant portions will bemade.

In the present embodiment, the transparent layers 50 are provided abovethe substrate 101, as shown in FIG. 14.

Specifically, the transparent layers 50 are formed over the respectivephotodiodes 21 and electrode light blocking layers 41 via the respectivepassivation films Es.

In the present embodiment, the transparent layers 50 are interposedbetween the pixel isolation and light blocking layers 42, as shown inFIG. 14. That is, the transparent layers 50 are buried in the portionspartitioned by the pixel isolation and light blocking layers 42, likethe color filters 51 d.

The transparent layers 50 are configured to allow the incident light topass therethrough toward the respective light receiving surfaces JS. Forexample, each of the transparent layers 50 is formed of a silicon oxidefilm into which boron and phosphorus are doped (BPSG film).

The color filters 51 d are provided above the respective transparentlayers 50, as shown in FIG. 14.

In the present embodiment, the surface of each of the color filters 51 dthat faces the light receiving surface JS of the correspondingphotodiode 21 is convexly curved toward the light receiving surface JSand hence functions as a plano-convex lens whose lower side is theconvex surface that focuses light on the light receiving surface JS.

Although not shown, the transparent layers 50 and the color filters 51 dare formed in the periphery of the imaging region PA as well as thecentral portion thereof.

[Manufacturing Method]

A method for manufacturing the above solid-state imaging device 1 d willbe described below.

FIGS. 15, 16 and 17 show a key portion formed in the steps of the methodfor manufacturing the solid-state imaging device 1 d in the fourthembodiment according to the invention. FIGS. 15, 16 and 17 show the samecross section as that shown in FIG. 14.

In the following description, the step of forming the transparent layers50 and the color filters 51 d will primarily be described.

(1) Formation of Transparent Layer 50

An initial transparent layer 50 is first formed, as shown in FIG. 15.

Before the formation of the initial transparent layer 50, the pixelisolation and light blocking layers 42 are formed, as shown in FIG. 8.

Thereafter, the initial transparent layer 50 is formed over thephotodiodes 21 and the light blocking portions 40 via the passivationfilms Es, as shown in FIG. 15.

For example, the initial transparent layer 50 is formed by using CVD toform a BPSG film so that the pixel isolation and light blocking layers42 are covered.

In this process, since the electrode light blocking layers 41 have beenformed and jut out convexly from the substrate 101, recesses are formedin the initial transparent layer 50 in correspondence with the lightreceiving surfaces JS. Thereafter, a thermal reflow process is carriedout to smoothly curve the surface of the initial transparent layer 50.

The curvature of each of the curved recesses can be adjusted as desiredby appropriately setting the concentrations of the boron and phosphorusin the BPSG film, the temperature and the period of the reflow process,and other factors.

(2) Adjustment of Thickness of Initial Transparent Layer 50

The thickness of the initial transparent layer 50 is then adjusted, asshown in FIG. 16.

In the present embodiment, the thickness of the thus formed initialtransparent layer 50 is adjusted by carrying out an etchback process.

Specifically, the thickness of the initial transparent layer 50 isadjusted in such a way that the top of each of the pixel isolation andlight blocking layers 42 is exposed.

(3) Formation of Color Filters 51 d

The color filters 51 d are then formed, as shown in FIG. 17.

In the present embodiment, the color filters 51 d are formed on theupper surfaces of the transparent layers 50 and buried between the pixelisolation and light blocking layers 42.

Specifically, the color filters 51 d are formed by applying aphotosensitive resin material containing a coloring agent.

The other portions are then provided. The solid-state imaging device 1 dis thus completed.

[Brief]

In the present embodiment, since each of the color filters 51 d isformed in such a way that it functions as a plano-convex lens whoselower side is the convex surface as described above, the color filter 51d focuses light on the corresponding light receiving surface JS.

When each of the color filters is not formed as a plano-convex lenswhose lower side is the convex surface, principal rays incident atdifferent angles have different optical path lengths through the colorfilters. In this case, sensitivity shading may occur across the angle ofview in some cases.

The configuration in the present embodiment, however, can make theoptical path lengths through the color filters 51 d equal to each othereven when the principal rays are incident at different angles.

Since the shading can be suppressed in the present embodiment, the imagequality of a captured image can further be improved in a preferredmanner.

5. Fifth Embodiment Device Configuration

FIG. 18 shows a key portion of a solid-state imaging device 1 e in afifth embodiment according to the invention.

FIG. 18 is a cross-sectional view, taken along the X direction, of a keypotion of the pixels arranged in the imaging region PA shown in FIG. 2.FIG. 18 shows a central portion of the imaging region PA.

As shown in FIG. 18, the solid-state imaging device 1 e in the presentembodiment differs from the solid-state imaging device 1 a in the firstembodiment in terms of the shape of color filters 51 e. The presentembodiment is the same as the first embodiment except the pointdescribed above and points associated therewith. No description of theredundant portions will be made.

Each of the color filters 51 e is configured to function as the core ofa light guide that guides light to the corresponding light receivingsurface JS with an air gap layer AG interposed between the color filter51 e and the corresponding light blocking portion 40, as shown in FIG.18. In this case, the refractive index of the air gap layer AG is lowerthan that of the color filter 51 e. That is, a light guide is formed onthe light receiving surface JS with the color filter 51 e being the coreand the air gap layer AG being the clad.

In the present embodiment, each of the color filters 51 e has a taperedshape whose width decreases in the depth direction z.

Although not shown, the air gap layer AG is also provided in theperiphery of the imaging region PA as well as in the central portionthereof.

[Manufacturing Method]

A method for manufacturing the above solid-state imaging device 1 e willbe described below.

FIGS. 19, 20, 21, and 22 show a key portion formed in the steps of themethod for manufacturing the solid-state imaging device 1 e in the fifthembodiment according to the invention. FIGS. 19, 20, 21, and 22 show thesame cross section as that shown in FIG. 18.

In the following description, the step of forming the color filters 51 ewill primarily be described.

(1) Formation of Polysilicon Film PL

A polysilicon film PL is first formed, as shown in FIG. 19.

Before the formation of the polysilicon film PL, the pixel isolation andlight blocking layers 42 are formed, as shown in FIG. 8.

Thereafter, the polysilicon film PL is formed over the photodiodes 21and the light blocking portions 40 via the passivation films Es, asshown in FIG. 19.

For example, CVD is used to form the polysilicon film PL so that thepixel isolation and light blocking layers 42 are covered.

(2) Adjustment of Thickness of Polysilicon Film PL

The thickness of the polysilicon film PL is then adjusted, as shown inFIG. 20.

In the present embodiment, the thickness of the thus formed polysiliconfilm PL is adjusted by carrying out an etchback process.

Specifically, the thickness of the polysilicon film PL is adjusted insuch a way that the polysilicon film PL is left in the portions wherethe air gap layer AG described above (see FIG. 18) is formed.

(3) Formation of Color Filters 51 e

The color filters 51 e are then formed, as shown in FIG. 21.

In the present embodiment, the color filters 51 e are formed on theupper surfaces of the polysilicon films PL and buried between the pixelisolation and light blocking layers 42.

Specifically, the color filters 51 e are formed by applying aphotosensitive resin material containing a coloring agent.

(4) Formation of Air Gap Layers AG

The air gap layers AG are then formed, as shown in FIG. 22.

In the present embodiment, the air gap layers AG are formed by removingthe polysilicon films PL.

FIG. 23 shows a portion where any one of the color filters 51 e isformed on the upper surface of the corresponding polysilicon film PL inthe fifth embodiment according to the invention.

As shown in FIG. 23, at the intersections of the portions extending inthe horizontal direction x and the portions extending in the verticaldirection y in the pixel isolation and light blocking layer 42, theformed polysilicon film PL is thick and hence not covered with the colorfilter 51 e. The surface of the polysilicon film PL is thereforeexposed.

The polysilicon film PL is removed in a dry etching process through theportions where the surface of the polysilicon film PL is exposed, asshown in FIG. 23. As a result, the air gap layer AG, which is an airlayer, is formed, as shown in FIG. 22.

The other portions are then provided. The solid-state imaging device 1 eis thus completed.

[Brief]

In the present embodiment, since each of the color filters 51 e isformed in such a way that it functions as a light guide as describedabove, the color filter 51 e guides light to the corresponding lightreceiving surface JS.

When the color filters 51 e are formed in the pixel isolation and lightblocking layers 42, the light may be attenuated by the electrode lightblocking layers 41 and the pixel isolation and light blocking layers 42,resulting in decrease in sensitivity in some cases. In particular, atthe end of the angle of view where incident principal rays are inclined,light is incident on the light blocking portions 40 and hence theproblem described above tends to occur, resulting in significantsensitivity shading.

According to the configuration in the present embodiment, however, thecolor filters 51 e guide light to the respective light receivingsurfaces JS.

Since the shading can be suppressed in the present embodiment, the imagequality of a captured image can further be improved in a preferredmanner.

6. Sixth Embodiment Device Configuration

FIG. 24 shows a key portion of a solid-state imaging device 1 f in asixth embodiment according to the invention.

FIG. 24 is a cross-sectional view, taken along the X direction, of a keypotion of the pixels arranged in the imaging region PA shown in FIG. 2.FIG. 24 shows a central portion of the imaging region PA.

As shown in FIG. 24, in the present embodiment, the solid-state imagingdevice 1 f has low refractive index layers ZG in place of the air gaplayers AG. The present embodiment is the same as the fifth embodimentexcept the point described above and points associated therewith. Nodescription of the redundant portions will be made.

Each color filter 51 f is configured to function as the core of a lightguide that guides light to the corresponding light receiving surface JSwith the corresponding low refractive index layer ZG interposed betweenthe color filter 51 f and the corresponding light blocking portion 40,as shown in FIG. 24. In this case, the refractive index of the lowrefractive index layer ZG is lower than that of the color filter 51 f.That is, a light guide is formed on the light receiving surface JS withthe color filter 51 f being the core and the low refractive index layerZG being the clad.

In the present embodiment, each of the low refractive index layers ZG isformed of, for example, a silicon oxide film.

Although not shown, the low refractive index layer ZG is also providedin place of the air gap layer AG in the periphery of the imaging regionPA as well as in the central portion thereof.

[Manufacturing Method]

A method for manufacturing the above solid-state imaging device 1 f willbe described below.

FIGS. 25, 26, and 27 show a key portion formed in the steps of themethod for manufacturing the solid-state imaging device 1 f in the sixthembodiment according to the invention. FIGS. 25, 26, and 27 show thesame cross section as that shown in FIG. 24.

In the following description, the step of forming the color filters 51 fwill primarily be described.

(1) Formation of Low Refractive Index Layer ZG

An initial low refractive index layer ZG is first formed, as shown inFIG. 25.

Before the formation of the initial low refractive index layer ZG, thepixel isolation and light blocking layers 42 are formed, as shown inFIG. 8.

Thereafter, the initial low refractive index layer. ZG is formed overthe photodiodes 21 and the light blocking portions 40 via thepassivation films Es, as shown in FIG. 25.

For example, the initial low refractive index layer ZG is formed byusing CVD to form a silicon oxide film so that the pixel isolation andlight blocking layers 42 are covered.

(2) Adjustment of Thickness of Initial Low Refractive Index Layer ZG

The thickness of the initial low refractive index layer ZG is thenadjusted, as shown in FIG. 26.

In the present embodiment, the thickness of the thus formed initial lowrefractive index layer ZG is adjusted by carrying out an etchbackprocess.

Specifically, the thickness is adjusted by carrying out the etchbackprocess in such a way that the top of each of the pixel isolation andlight blocking layers 42 is exposed.

(3) Formation of Color Filters 51 f

The color filters 51 f are then formed, as shown in FIG. 27.

In the present embodiment, the color filters 51 f are formed on theupper surfaces of the low refractive index layers ZG and buried betweenthe pixel isolation and light blocking layers 42.

Specifically, the color filters 51 f are formed by applying aphotosensitive resin material containing a coloring agent.

The other portions are then provided. The solid-state imaging device 1 fis thus completed.

[Brief]

In the present embodiment, since each of the color filters 51 f isformed in such a way that it functions as a light guide as describedabove, the color filter 51 f guides light to the corresponding lightreceiving surface JS.

Since the shading can be suppressed in the present embodiment, the imagequality of a captured image can further be improved in a preferredmanner, as in the fifth embodiment.

7. Seventh Embodiment Device Configuration and Others

FIG. 28 shows a key portion of a solid-state imaging device 1 g in aseventh embodiment according to the invention.

FIG. 28 is a cross-sectional view, taken along the X direction, of a keypotion of the pixels arranged in the imaging region PA shown in FIG. 2.FIG. 28 shows a peripheral portion of the imaging region PA. On theother hand, a central portion of the imaging region PA is the same asthat shown in FIG. 10.

As shown in FIG. 28, the solid-state imaging device 1 g in the presentembodiment differs from the solid-state imaging device 1 b in the secondembodiment in terms of on-chip lenses 61 g in the peripheral portion ofthe imaging region PA. The present embodiment is the same as the secondembodiment except the point described above and points associatedtherewith. No description of the redundant portions will be made.

As seen by comparing FIG. 28 with FIG. 10 described above, each of theon-chip lenses 61 g is formed in such a way that the thickness thereofincreases with distance from the center toward the periphery of theimaging region PA. That is, the thickness is small at the center of theangle of view, whereas the thickness is large at the end of the angle ofview.

[Brief]

As described above, in the present embodiment, the pixel isolation andlight blocking layers 42 are formed in the same manner as in the secondembodiment. That is, the pixel isolation and light blocking layers 42are formed to include portions in which the widths G31, G32, G33, G34, .. . of the spaces between the pixel isolation and light blocking layers42 increase with distance from the center toward the periphery of theimaging region PA.

In addition to the above, each of the on-chip lenses 61 g is formed insuch a way that the thickness thereof increases with distance from thecenter toward the periphery of the imaging region PA, as describedabove.

It is therefore possible in the present embodiment to effectively focuslight at the end of the angle of view and suppress shading in a capturedimage.

In the present embodiment, the image quality of a captured image cantherefore be improved.

8. Others

The invention is not necessarily implemented in the manner as in theembodiments described above, but a variety of variations can beemployed.

For example, while the above embodiments have been described withreference to the case where a CCD image sensor is used, a CCD imagesensor is not necessarily used. For example, any other one of a varietyof image sensors, such as a CMOS image sensor, can be used.

Further, in each of the three primary color filters, the thickness ofthe corresponding on-chip lens may be optimized by appropriatelyadjusting the thickness.

While the above embodiments have been described with reference to thecase where the invention is applied to a camera, the invention is notnecessarily applied to a camera. The invention may be applied to ascanner, a copier, or any other electronic apparatus including asolid-state imaging device.

In addition to the above, the spirit of the invention may be combined asappropriate.

In the embodiments described above, the solid-state imaging devices 1, 1b, 1 c, 1 d, 1 e, 1 f, and 1 g correspond to the solid-state imagingdevice according to an embodiment of the invention. In the embodimentsdescribed above, the substrate 101 corresponds to the substrateaccording to an embodiment of the invention. In the embodimentsdescribed above, the imaging region PA and the imaging surface PScorrespond to the imaging surface according to an embodiment of theinvention. In the embodiments described above, the light receivingsurface JS corresponds to the light receiving surface according to anembodiment of the invention. In the embodiments described above, thephotodiode 21 corresponds to the photoelectric conversion elementaccording to an embodiment of the invention. In the embodimentsdescribed above, the transfer electrode 31 corresponds to the electrodeaccording to an embodiment of the invention. In the embodimentsdescribed above, the light blocking portion 40 corresponds to the lightblocking portion according to an embodiment of the invention. In theembodiments described above, the extending portions 41 x and 41 y in theelectrode light blocking layers 41 correspond to the electrode lightblocking portions according to an embodiment of the invention. In theembodiments described above, the extending portions 42 x and 42 y in thepixel isolation and light blocking layer 42 correspond to the pixelisolation and light blocking portion according to an embodiment of theinvention. In the embodiments described above, the first pitch P1corresponds to the first pitch according to an embodiment of theinvention. In the embodiments described above, the second pitch P2corresponds to the second pitch according to an embodiment of theinvention. In the embodiments described above, the third pitch P3corresponds to the third pitch according to an embodiment of theinvention. In the embodiments described above, the color filters 51, 51d, 51 e, and 51 f correspond to the color filter according to anembodiment of the invention. In the embodiments described above, theon-chip lenses 61 and 61 g correspond to the on-chip lens according toan embodiment of the invention. In the embodiments described above, thecamera 200 corresponds to the electronic apparatus according to anembodiment of the invention.

The present application contains subject matter related to thatdisclosed in Japanese Priority Patent Application JP 2009-035761 filedin the Japan Patent Office on Feb. 18, 2009, the entire contents ofwhich is hereby incorporated by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A solid-state imaging device comprising: aplurality of photoelectric conversion elements disposed on an imagingsurface of a substrate, each of the photoelectric conversion elementsreceiving light incident on a light receiving surface and performingphotoelectric conversion to produce a signal charge; a plurality ofelectrodes interposed between the photoelectric conversion elementsarranged on the imaging surface of the substrate; and a plurality oflight blocking portions provided above the plurality of electrodes andinterposed between the photoelectric conversion elements arranged on theimaging surface of the substrate, wherein each of the light blockingportions includes an electrode light blocking portion formed to coverthe corresponding electrode, and a pixel isolation and light blockingportion protruding convexly from the upper surface of the electrodelight blocking portion, the plurality of photoelectric conversionelements are arranged at first pitches on the imaging surface, theelectrode light blocking portions in the plurality of light blockingportions are arranged at second pitches on the imaging surface, thepixel isolation and light blocking portions in the plurality of lightblocking portions are arranged at third pitches on the imaging surface,and at least the third pitch increases with distance from the centertoward the periphery of the imaging surface.
 2. The solid-state imagingdevice according to claim 1, wherein the plurality of photoelectricconversion elements is formed in such a way that the first pitch and thearea of the light receiving surface increase with distance from thecenter toward the periphery of the imaging surface, and the electrodelight blocking portions in the plurality of light blocking portions areformed in such a way that the second pitch increases with distance fromthe center toward the periphery of the imaging surface.
 3. Thesolid-state imaging device according to claim 2, wherein the pluralityof photoelectric conversion elements, the electrode light blockingportions in the plurality of light blocking portions, and the pixelisolation and light blocking portions in the plurality of light blockingportions are formed in such a way that the first, second, and thirdpitches increase at the same rate over the imaging surface from thecenter toward the periphery thereof.
 4. The solid-state imaging deviceaccording to claim 1, wherein the plurality of photoelectric conversionelements and the plurality of electrode light blocking portions aredisposed in such a way that the first pitch is equal to the second pitchover the imaging surface from the center toward the periphery thereof.5. The solid-state imaging device according to claim 1, furthercomprising color filters disposed above the photoelectric conversionelements in correspondence with the plurality of photoelectricconversion elements, wherein the color filters are interposed betweenthe plurality of pixel isolation and light blocking portions arranged onthe imaging surface.
 6. The solid-state imaging device according toclaim 5, wherein each of the color filters has a surface facing thecorresponding light receiving surface and convexly curved toward thelight receiving surface and functions as a plano-convex lens whose lowerside is the convex surface that focuses light on the light receivingsurface.
 7. The solid-state imaging device according to claim 5, whereina layer having a refractive index lower than that of the color filtersis interposed between each of the color filters and the correspondinglight blocking portion, and each of the color filters functions as thecore of a light guide that guides light to the corresponding lightreceiving surface.
 8. The solid-state imaging device according to claim1, further comprising a plurality of on-chip lenses provided above theplurality of photoelectric conversion elements in correspondence withthe photoelectric conversion elements.
 9. The solid-state imaging deviceaccording to claim 8, wherein the on-chip lenses are formed in such away that the area thereof increases with distance from the center towardthe periphery of the imaging surface.
 10. The solid-state imaging deviceaccording to claim 8, herein the on-chip lenses are formed in such a waythat the thickness thereof increases with distance from the centertoward the periphery of the imaging surface.
 11. An electronic apparatuscomprising: a plurality of photoelectric conversion elements disposed onan imaging surface of a substrate, each of the photoelectric conversionelements receiving light incident on a light receiving surface andperforming photoelectric conversion to produce a signal charge; aplurality of electrodes interposed between the photoelectric conversionelements arranged on the imaging surface of the substrate; and aplurality of light blocking portions provided above the plurality ofelectrodes and interposed between the photoelectric conversion elementsarranged on the imaging surface of the substrate, wherein each of thelight blocking portions includes an electrode light blocking portionformed to cover the corresponding electrode, and a pixel isolation andlight blocking portion protruding convexly from the upper surface of theelectrode light blocking portion, the plurality of photoelectricconversion elements are arranged at first pitches on the imagingsurface, the electrode light blocking portions in the plurality of lightblocking portions are arranged at second pitches on the imaging surface,the pixel isolation and light blocking portions in the plurality oflight blocking portions are arranged at third pitches on the imagingsurface, and at least the third pitch increases with distance from thecenter toward the periphery of the imaging surface.
 12. A method formanufacturing a solid-state imaging device, the method comprising thesteps of: forming a plurality of photoelectric conversion elements on animaging surface of a substrate, each of the photoelectric conversionelements receiving light incident on a light receiving surface andperforming photoelectric conversion to produce a signal charge; forminga plurality of electrodes interposed between the plurality ofphotoelectric conversion elements arranged on the imaging surface of thesubstrate; and forming a plurality of light blocking portions above theplurality of electrodes and between the plurality of photoelectricconversion elements arranged on the imaging surface of the substrate,wherein the step of forming the light blocking portions includes thesteps of forming an electrode light blocking portion that covers thecorresponding electrode, and forming a pixel isolation and lightblocking portion protruding convexly from the upper surface of theelectrode light blocking portion, in the step of forming thephotoelectric conversion elements, the plurality of photoelectricconversion elements are arranged at first pitches on the imagingsurface, in the step of forming the electrode light blocking portions,the electrode light blocking portions are arranged at second pitches onthe imaging surface, and in the step of forming the pixel isolation andlight blocking portions, the pixel isolation and light blocking portionsare arranged at third pitches on the imaging surface and the third pitchincreases with distance from the center toward the periphery of theimaging surface.